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  <title>Document</title>
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  <script>
    const p1 = new Promise((resolve, reject) => {
      try {
        console.log("开始请求A.....")
        throw new Error("网络出现问题!!!!")
        setTimeout(() => {
          console.log("数据请求成功");
          resolve({
            token: "hskahdoqwhdlkash"
          })
        }, 2000)
      } catch (e) {
        reject(e.message)
      }
    })

   
    p1.then(value => {

    })
    const p2 = p1.catch((reason)=>{
      return new Promise((resolve, reject) => {
        resolve(2)
      })
    })
    /* 
      catch方法:
        - 当调用catch方法的promise实例变为失败状态,则会执行catch中的回调函数
        - catch的作用和then方法的第二个回调函数的作用一致
        - catch方法的返回值和then方法的返回值规则保持一致
    
    
    */
    // const p2 = p1.catch(reason => {
    //   return new Promise((resolve, reject) => {
    //     resolve(1)
    //   })
    // })
    console.log("p2", p2);
  </script>
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